1. Field of the Invention
The subject invention is directed to heavy-duty vehicle drum brakes.
2. Related Art
Despite the increasing popularity of disc brakes, drum brakes remain a popular choice for many braking applications. Conventional drum brake assemblies include a circular drum and a pair of shoes, each with at least one brake lining disposed thereon. During braking, the shoes are pushed against an inner surface of the drum, which generates friction between the brake linings and the drum. This friction converts kinetic energy from the movement of the vehicle into heat, thereby slowing the vehicle. The friction also causes the brake linings to wear out, and therefore, the brake linings have to be periodically replaced.
Known problems with drum brakes include excessive vibrations and noise which can occur during braking. Apart from agitating the occupants of the vehicle and the general public, such vibrations can reduce the performance of the brakes. For passenger vehicles, brake manufacturers have begun producing brake linings with leading and trailing chamfered edges in order to reduce the braking vibrations and noise. The chamfered edges of most prior art brake linings are very steeply angled and comprise only a small portion of the brake lining. While effective for smaller vehicles, brake linings having steeply angled and short chamfered edges may not eliminate all noise and vibrations for heavy-duty vehicles.